This wasn't an effort at reforestation - on closer inspection, the mountain looked the colour of astroturf. Laoshou mountain has been spraypainted green.

Official Chinese media reported that the presumably weatherproof paint was applied at a cost of around $60,000. When western media tried to follow up with the forestry department of Fumin County, a panicked woman would only say to the AP newswire: "This is an order from above. You should ask the leader from above. I don't have any information on this." Then she hung up. She refused to give her name.

This would be just another quirky story if it came from your run-of-the-mill tinpot dictatorship. But the secret mountain paint-job comes from one of the pillars of the global economy, about which we hear so much and understand so little.

One thing that has entered our collective consciousness is that China is huge and has become the world's lowcost factory.

So last Monday, when the Shanghai stock market cratered, losing nine percent of its value in one session, it marked the beginning of a week in which markets tanked in country after country.

In Ireland, it meant that by the end of the week, Irish share prices turned back the clock to the end of January, giving up their seven percent gains for the month of February.

By the start of the weekend, commentators were downplaying the China element of the story. It was because of the comments a week ago by former US Federal Reserve chairman Alan Greenspan, speculating that the US economy might experience a slowdown. Or it was because of the fact that one out of every five so-called 'sub-prime' mortgages (loans made to home owners with less-than-perfect credit) was in default, signalling further trouble in the US housing market. Or perhaps it was - as our Market Monkey columnist writes in today's Business section - simply some long-overdue profittaking, where, soon after major stock markets had touched new record highs (coming back to prices last achieved in the dotcom era), it was time to take a breather.

China is an immature market, goes the argument. And immature markets are prone to volatility. It shouldn't matter what happens in Shanghai, where the stock market only re-opened in 1990 after being shut for 40 years as a symbol of the evils of capitalism.

Even now, foreigners are not allowed to directly invest in Chinese equities.

And the companies listed on the Shanghai exchange tend, paradoxically, to be more about state-owned companies raising money than in the really booming parts of the private sector.

To add to the confusion, the Shanghai downturn itself was brought about by market rumours that the Chinese government was going to crack down on people borrowing money to invest in the stock market and perhaps introducing a capital-gains tax. In other words, the Chinese were trying to better regulate the trading of shares to bring it more in line with Western standards.

So with all of that, you have to ask why a dip in shares of former state monopolies traded by Mahjong grannies should mean your pension or SSIA is worth a little less this week.

Partly, it's because the western world is now so interdependent with China - as a consumer of raw materials and oil, as a lender of money to the US government, as a market in and of itself. Many of the stocks that suffered the biggest falls in subsequent days were in the mining and energy sectors, which stand to lose the most if their new best customer doesn't need to buy as much.

But it may be that we're nervous - not without reason - that our sudden interdependence with China, which has brought us innumerable benefits of cheaper consumer goods, lower inflation and consequently lower interest rates that have kept the global economy humming along, might have hidden risks. Risks that Chinese bureaucrats would just as soon paint over. Like Laoshou Mountain.